NEW YORK (MainStreet)It's no secret that the Internet has turned travel on its head. Thanks to resources like web-based booking, online currency conversions and networked ATMs, everyone has become his own travel agent and can make plans on the fly. Sometimes literally. Travel websites have dropped the barriers to entry, turning formerly insurmountable problems like tracking political unrest into little more than an inconvenience. (As this writer once discovered firsthand.) A good browser history is, these days, an indispensible part of any traveler's toolkit. Over the years I've collected a number of different websites that help with the many moving pieces of going overseas. They range from the useful to the outright essential, but one thing's for sure: like the old saying goes, you should never leave home without them. With that in mind, here are a few links that have earned a place at the top of my bookmarks.